Beyond the physical, mechanical and technical performance, the audio portion of a headset must sound good to the user and the party on the far end. Sound is subjective and Cisco cannot guarantee the performance of any headsets or handsets, but some of the headsets and handsets on the sites listed below have been reported to perform well on Cisco IP Phones.
Nevertheless, it is ultimately still the customer's responsibility to test this
equipment in their own environment to determine suitable performance. For
information about headsets, see:
I remember some customers using those models you mentioned in 7941|7960|7961 without an issue.
You may test them and check out,
You should be fine with the 9120 (I have used/tested this model) It also is shown as compatible on the GN Netcom/Jabra guide. The CA/CS10 is hard to say, and is EOL so not listed in the Plantronics reference info. I certainly don't see why it wouldn't work.
GN Netcom/Jabra Compatibility;
Hope this helps!
Make sure you take out the power amplifier, we use many different versions of the plantronics headsets on our 7961 phones without any problems at all.